Blood transfer device

ABSTRACT

A blood transfer device for veni-puncture and the like is provided having a double-pointed cannula, a main chamber for loading and reloading cartridges, and a pilot chamber separated from the main chamber by a resilient collapsible cannula sheath. When the device is used and the cannula is correctly positioned as for veni-puncture, the blood enters the cannula and flows into the pilot chamber through certain aperture means between the cannula and the pilot chamber enabling the operator to confirm visually by the presence of a substantial sample that the placement is correct. One injection serves for the loading and filling of several cartridges, as desired, without spilling of blood between loadings and with minimum risk of exposure to contamination, etc.

I United States Patent l 13,585,984

[72] Inventor Robert A. Buchanan 3,200,813 8/1965 Christakis 128/2 AnnArbor. Mich- 3,469,572 9/1969 Nehring 128/2 112 1968 PrimaryExaminerWamer H. Camp I AttorneysRobert R. Adams, David B. Ehrlinger,George M. [45] Patented June 22, 1971 h d d Ed d J Ga" [73] AssigneeParke Davis 8: Company at s an war Detroit, Mich.

[541 BLOOD TRANSFER DEVICE ABSilRCT: blood transfer device forveni-puncture and 1 Cum, 6 Drawing as. the like 15 provided having adouble-polnte d cannula, a main chamber for loading and reloadingcartridges, and a plot 128/2, chamber separated from the main chamber bya resilient col- 123/276 lapsible cannula sheath. When the device isused and the can- [5 l 1 Int. nula is orre tl o itioned as for venipuncture the en- [50] Field of Search 128/2, 214, tel-S the canmfla andfl into the pilot chamber through 216, 5 tain aperture means between thecannula and the pilot chamber enablin the o erator to confirm visuall bythe [56] References cued presence of a subs tantial sample that theplacement is correct. UNITED STATES PATENTS One injection serves for theloading and filling of several car- 3,500,821 3/1970 Ogle 128/2 tridges,as desired, without spilling of blood between loadings 3,200,486 8/1965Shields 128/215 X and with minimum risk of exposure to contamination,etc.

BLOOD TRANSFER DEVICE SUMMARY AND DETAILED DESCRIPTION This inventionrelates to blood transfer devices and more particularly to bloodtransfer devices for veni-puncture and the like assuring the correctplacement of the cannula within the vein.

Heretofore the devices commonly used for veni-puncture, bloodwithdrawal, parenteral administration, etc. have generally suffered fromthe disadvantage that means were lacking for determining readily whetheror not the cannula end was correctly placed in the vein. For bloodwithdrawal purposes, for example, where the cannula is incorrectlyplaced, an insufficient blood sample is obtained or the site ofinjection becomes traumatized through misplacement, misadventure, etc.On the other hand, in devices which incorporate features for thedetection of venous blood prior to the main sample, the construction hasbeen unduly complicated or difficult to manipulate or the volume offluid transferred with each injection has been unduly restricted.

It is therefore an object of the present invention to provide simple,inexpensive means for detecting the correct placement of blood transferdevices for intravenous injection. It is also an object of the inventionto provide blood transfer devices having a main chamber and a separatepilot chamber-the latter chamber being useful for initial collection ofthe blood sample to determine visually whether or not the device iscorrectly oriented for access to the vein.

It is a further object of the invention to provide blood transferdevices which can be used either for the withdrawal of blood samples orfor the administration of drugs, medicaments and the like, or for bothin a single injection and in any desired volume.

Other objects, features and advantages will be apparent from thespecification which follows, in conjunction with the accompanyingdrawing in which:

FIG. 1 is a side view of a preferred blood transfer device of theinvention, partly cut away to show details in the construction of thecannula and associated sheath means;

FIG. 2 is a cross section of the preferred device shown in FIG. I takenon a line 2-2 designated in FIG. 3;

FIG. 3 is an end view taken on line 3-3 of FIG. 1 of a blood transferdevice of the invention;

FIG. 4 is an enlarged partial section of another preferred embodiment ofthe invention showing the cannula piercing the sheath means andcartridge stopper and also illustrating the collapsed position of thesheath means;

FIG. 5 is a sectional view of the cannula and sheath means taken on line5-5 of FIG. I, and FIG. 6 is a similar view showing channels 19 betweenthe cannula and collar 21.

Referring to FIGS. 1 and 2 of the drawing, the blood transfer deviceincludes a holder 10 defining a main chamber 11 and a pilot chamber 12.The pilot chamber is defined by a hub 13 and the neck portion 14. Thehub 13 serves as a mounting for a cannula 15. The opposite end of theholder has an open end 16 for receiving cartridges containing drugs,vaccines or the like for administration under pressure or cartridgesevacuated for blood collection purposes. The cartridge 23 (partly shownin FIG. 4) can take any of a number of various forms known in the art.Surrounding the opening are the flanges 17 providing means forconveniently gripping the holder 10.

The cannula has an outer end 1811 for injection and an inner end 1811.It also includes aperture means 19 located generally midway between theends of the cannula in communication with the pilot chamber 12.Surrounding the inner end 18b of the cannula 15 is sheath means 20 atthe base of which is a supporting collar 21.

The sheath means 20 with its collar 21 serves as a fluid-impervious sealbetween the pilot chamber 12 and the main chamber 11. It is resilientand flexible, particularly in the sheath portion; it is also resealableor self-sealing when punctured. The term sheath means" is sometimes usedherein in a general sense to include both elements 20 and 21 and will beso understood. The sheath means operates according to the invention intwo positions: In one position, it extends into the unloaded mainchamber 11 as shown in FIGS. 1 and 2 where it surrounds the cannula end18b and walls off the main chamber from the pilot chamber 12. In theother position, the sheath means, when contacted in an axial directionby a cartridge 23 (e.g., a cartridge of the type illustrated in U.S.Pat. No. 3,366,l03) being loaded into the chamber, is forced against andpierced by the pointed inner end 18b of the cannula, and is collapsed asillustrated in FIG. 4 with the result that the lumen of the cannula isin open communication with the interior of the cartridge. In turn, whenthe cartridge is withdrawn, the sheath spontaneously reseals itself andflexes back to its original position.

As shown in FIG. 3, the holder in a preferred form is generallycylindrical with the cannula l5, hub 13 and neck 14 in axial alignmentalong the central axis of the holder.

The embodiment shown in collapsed form in FIG. 4 is a preferredconstruction where instead of aperture means intermediate the outer andinner ends of the cannula there is provided an annular open zone 19within the body of the sheath means 20 surrounding the cannula wherebyblood entering the cannula is in open communication with the pilotchamber 12 and is free to move and distribute itself within the confinesof the pilot chamber. Prior to collapsing, the sheath means of FIG. 4assumes the position free of end 18b, as in the unflexed position shownin FIG. 2. In the embodiments of FIGS. 1, 2 and 4 the wall portions ofthe hub 13, neck 14 and/or sheath means 20 are conveniently made oftransparent or translucent material so that blood contained in the pilotchamber can be readily observed. By this means the device can be usedfor veni-puncture and the like by inserting the outer end 18a into thevein so that the blood enters and passes through the cannula into thepilot chamber 12 by way of the aperture means 19 as seen in FIGS. 1 and2 or the aperture means 19 within the sheath means 20, as seen in FIG.4. In this case if the cannula 15 is correctly positioned within thevein the venous pressure serves to pump the blood free into the pilotchamber sub- .stantially filling the same so that a distinct and sharpvisual red coloration may be readily observed. On the other hand, wherethe placement of the cannula 15 is incorrect the supply of venous blood,if any, reaching the pilot chamber is only slight thereby giving directvisual indication of an improper placement of the cannula. The sheathmeans 20 in any case serves to prevent the entry of blood into the mainchamber 1]. Thus, when it is desired for purposes of the invention totake a blood sample, the injection is made to provide visual indicationin the pilot chamber 12 of the correct placement of the cannula. Avacuum cartridge is then inserted into the main chamber 11 through theopen end 16 until its stopper contacts sheath means 20 and collapses thesame upon the inner end 18b of the cannula 15, causing the sheath meansto be pierced so that the inner end 18b of the cannula reaches theevacuated zone. The resulting high-pressure differential causes blood toflow from the vein through the cannula 15 into the cartridge. Theprocedure is continued until the cartridge is sufficiently full forsampling purposes. The cartridge is then withdrawn from the chamber 11.As a consequence of withdrawal and because the sheath means 20 isresilient, flexible and resealable, the sheath means flexes back intothe position illustrated so that the cannula 15 is sealed off againstfurther blood flow into the main chamber 11. At this point, the cannulacan be withdrawn from the vein or, if desired, fresh cartridges can inturn be loaded and filled without interruption and without the need formaking a new injection for the filling of each tube. Substantially thesame procedure using pressure cartridges instead of vacuum cartridgescan be followed. Thus, when the correct placement of the cannula 15 isobtained as indicated by the ample supply of venous blood in the pilotchamber 12 the medicament cartridge can then be loaded into the chamber11, whereupon the positive pressure present in the cartridge serves tocause the medicament contents to move through the cannula into the veinuntil the pressure is equalized.

The aperture means [9 can take any of various forms including an openingbetween the ends of the cannula (FIG. 1), an annular open zone ofuniform section separating the collar and sheath from the cannula (FIG.4), and channels 19 (FIG. 6) at the interface between the collar andcannula. Other equivalent forms will be suitable.

The makeup of the various components employed in the blood transferdevices of the invention can be of any conventional material. Thus, thecannula will ordinarily be of high grade surgical stainless steel. Theholder 10 can be made of glass, plastic or other suitable inertmaterial, preferably transparent and readily sterilizable. The sheathmeans and collar 21, suitably made of gum rubber, elastomeric plastic orthe like, should be impervious to fluids and resilient so as to providethe required seal between the pilot chamber 12 and main chamber 11. Inparticular, the sheath means 20 should be sufficiently resilient to bepierced and collapsed by the insertion of a cartridge in chamber 11 andyet to flex back and reseal in its original position covering the innerend of the cannula 18b when the cartridge is withdrawn from the chamber.As an optional feature shown in FIG. 4, the collar 21 can be made of asomewhat more rigid material and can be anchored into the neck 14 inseating relationship within the channel 22, secured if necessary byadhesive or other suitable means.

While the invention has been described in detail in the foregoingspecification, it will be realized by those skilled in the art thatconsiderable variation can be made in such detail without departing fromthe spirit of the invention.

lclaim:

l. A blood transfer device comprising: a holder including a hub, a neckand an axially extending main chamber adapted to receive a cartridge;

a cannula having piercing outer and inner ends;

means for mounting the inner end of the cannula in axial alignmentwithin the holder for piercing contact with a cartridge inserted in theholder;

pierceable sheath means adapted in a firstposition to enclose the innerend of the cannula and sealingly prevent blood in the cannula fromentering the main chamber and further adapted in a second position witha cartridge inserted in said piercing contact in the holder to bepierced by the inner end of the cannula and to expose the same for fluidtransfer with respect to the cartridge, the sheath means being fixedlymounted by collar means within the neck and being resilient such thatupon withdrawal of a cartridge from the main chamber the sheath meansflexes back to said first position and reseals;

a pilot chamber defined by the hub, neck and collar means, the pilotchamber being separate from the main chamber and includinglight-transmissive wall means for viewing the presence of bloodcollected in the pilot chamber; and

aperture means including an opening in the cannula wall between the endsof the cannula, the opening being in direct communication with the pilotchamber whereby, prior to insertion of a cartridge, blood under tensionentering the outer end of the cannula has direct access for distributionto the pilot chamber for visual observation.

1. A blood transfer device comprising: a holder including a hub, a neckand an axially extending main chamber adapted to receive a cartridge; acannula having piercing outer and inner ends; means for mounting theinner end of the cannula in axial alignment within the holder forpiercing contact with a cartridge inserted in the holder; pierceablesheath means adapted in a first position to enclose the inner end of thecannula aNd sealingly prevent blood in the cannula from entering themain chamber and further adapted in a second position with a cartridgeinserted in said piercing contact in the holder to be pierced by theinner end of the cannula and to expose the same for fluid transfer withrespect to the cartridge, the sheath means being fixedly mounted bycollar means within the neck and being resilient such that uponwithdrawal of a cartridge from the main chamber the sheath means flexesback to said first position and reseals; a pilot chamber defined by thehub, neck and collar means, the pilot chamber being separate from themain chamber and including light-transmissive wall means for viewing thepresence of blood collected in the pilot chamber; and aperture meansincluding an opening in the cannula wall between the ends of thecannula, the opening being in direct communication with the pilotchamber whereby, prior to insertion of a cartridge, blood under tensionentering the outer end of the cannula has direct access for distributionto the pilot chamber for visual observation.